A second Republican has jumped into the Louisiana Senate race to challenge Democratic Sen. Mary Landrieu, considered among the most vulnerable incumbents in 2014.

Rob Maness, a retired Air Force Colonel who has never run for public office, announced Monday that he is entering the race. Republican Rep. Bill Cassidy is also challenging Landrieu.

“After serving 32 years in the military devoted to supporting and defending the Constitution from threats outside of America, I realized when my peers and I were facing out, behind us the political class in office was not living up to their oath to support and defend the Constitution,” Maness told The Daily Caller via email on Monday.

Asked what he brings as a candidate that neither Landrieu nor Cassidy does, Maness said it was his sense of principle.

“We need men and women in Congress who legislate from set of principles not from public opinion polls,” he said. “I will stand on principle. I will read each piece of legislation through the lens of the Constitution. I will stand with Rand Paul, Ted Cruz, Mike Lee and stand alone when needed.”

Louisiana has an open primary system, meaning all candidates, Democratic, Republican and from other parties, are placed on one ballot. If no candidate gets fifty percent of the vote, the top two vote-getters go to a run-off.

Maness said he was unconcerned about splitting the vote with Cassidy and giving Landrieu a victory, taking a jab at the viability of his opponent.

“Competition is good. The voters deserve the best we can offer,” he said. “We don’t believe that Rep. Cassidy will take away enough votes from us for it to be a concern.”

Maness dismissed Cassidy’s candidacy in general, saying he would not be able to beat Landrieu.

“Rep. Cassidy is a nice man and a loyal Rove Republican,” Maness said, “and that is the problem. A Rove Republican can’t beat Mary Landrieu.”